An exploratory investigation of neuroinflammatory and nociceptive biomarkers from cerebrospinal fluid in children with cerebral palsy following intrathecal baclofen pump implant surgery

An exploratory investigation of neuroinflammatory and nociceptive biomarkers from cerebrospinal fluid in children with cerebral palsy following intrathecal baclofen pump implant surgery | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article An exploratory investigation of neuroinflammatory and nociceptive biomarkers from cerebrospinal fluid in children with cerebral palsy following intrathecal baclofen pump implant surgery Frank J Symons, Annette Steen-Hansen Krøglid, Maykala Williams, and 5 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7277982/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 21 You are reading this latest preprint version Abstract Background Cerebral palsy (CP) is the most common cause of disability in children. Cerebral palsy (CP) is the most common cause of disability in children. For children with CP, muscle spasticity is often a cause of chronic pain. Surgical implant of an intrathecal baclofen (ITB) pump is a typical method to treat spasticity. Most studies have documented a reduction in spasticity upon ITB implant; however, less is known about other outcomes, including pain reduction. Little is known about spasticity-related muscle pain in general. Sustained muscle fiber contraction over time, resulting in local ischemia, may result in pathological inflammatory and nociceptive consequences affecting excitatory or inhibitory circuits peripherally but also centrally. Examining inflammatory and nociceptive biomarkers could be especially important in children with CP, who have high rates of chronic pain and typically undergo multiple surgeries in their lifetime. Surgery has been associated with increases in inflammatory biomarker levels which predict important outcomes such as time to healing. This study investigated changes in levels of nociceptive and inflammatory-relevant molecules in cerebral spinal fluid (CSF) from a clinical-convenience sample of children with CP being treated for spasticity through standard-of-care ITB pump implant surgery for hypothesis-generating research purposes. Methods Fourteen children with CP participated (7 male, mean age at surgery = 9 years, 8 months [SD = 2.25]). CSF was collected during surgery and again, on average, 8.5 months (SD = 4.4) after surgery during baclofen pump refill. Wilcoxon signed rank tests were used to compare analyte levels. Results Significant differences were observed for the rank ordered values (pg/ml) for the three interleukins (IL-1RA: Median pre = 38.4/post = 213.6; IL-8: Median pre = 23.5/post = 39.7; IL-10: Median pre = 0.7/post = 0.7 [Mean values for IL-10 were pre = 0.68/post = 0.92], p < .05). Conclusions The main but tentative preliminary finding points to increased analyte levels from the interleukin family. Interleukins regulate immune responses often with pro- and anti-inflammatory properties. Our observations of increased CSF IL-10 and IL-8 are consistent with similar observations of increases post-procedure and some limited observations of IL-1RA elevations in chronic pain. Understanding inflammatory response profiles in CP could lead to important treatment and pain outcome implications. Intrathecal baclofen pain biomarkers interleukin cerebral spinal fluid cerebral palsy developmental disability Figures Figure 1 Figure 2 Figure 3 Introduction Cerebral Palsy (CP) is the most common congenital cause of disability in children affecting approximately 2/1000 live births depending on global region.[1] Spasticity is reported in approximately 80% of those with CP and, depending on severity, results in chronic pain and interferes with function and comfort. Intrathecal baclofen (ITB) is regarded as relatively effective in the reduction of spasticity and is frequently used to treat hypertonicity associated with CP. Although almost all studies report changes in muscle tone, the evidence for other outcomes including pain reduction is less clear and often there are individuals for whom pain persists, but this is not well understood mechanistically.[2] In contrast to cutaneous pain, much less is known about the origins and mechanisms of spasticity-related muscle pain.[3] Some experimental models based on inflammation (injection of hypertonic saline, carrageenan) show that inflammatory mediators (bradykinin, serotonin, prostaglandin) released after muscle damage, sensitize muscle nociceptors by site-specific binding.[4] Muscle pain that is the product of chronic spasticity may not spontaneously resolve and may become persistent and, in this sense, pathological. It could, therefore, be the case that the initial local ischemia from sustained muscle fiber contraction has several potential deleterious ‘downstream’ effects including pathophysiological inflammatory and nociceptive consequences affecting excitatory or inhibitory circuits peripherally but also centrally. There is also an emerging viewpoint on the role of central neuro-inflammation consistent with documented early white matter damage leading to CP and, from our perspective, this is a possible pathophysiological contributor to the biology of chronic pain mechanisms in CP.[5] Children with CP routinely undergo more surgeries compared to their peers, which in other samples and models, has typically been associated with pronounced increases in inflammatory biomarkers.[6-8] These inflammatory increases have predicted important postoperative outcomes, such as time to healing and cognitive decline; outcomes potentially of particular value in CP given the associated sequelae and medical needs.[6, 9, 10] In this exploratory study we assessed nociceptive- and inflammatory-relevant molecules in cerebral spinal fluid (CSF) from a convenience sample of children with CP being treated for spasticity through standard-of-care ITB implant surgery for hypothesis-generating research purposes. The primary aim of this study was to investigate whether levels of nociceptive- and inflammatory-relevant molecules increased following ITB implant surgery. The secondary aim of this study was to investigate potential intercorrelations in CSF cytokines at each time point. Methods This study was conducted in accordance with the ethical principles of the Declaration of Helsinki and approved by the Institutional Review Board of the University of Minnesota. Clinical trial number: not applicable. Written informed consent was obtained from each child’s parent or legal representative. Assent to participate was obtained from each child over the age of eight who was cognitively able to understand the materials in simplified language. A clinical convenience sample was formed for a molecular biomarker measurement during ITB pump implant surgery (Time 1 [T1]) and after surgery during baclofen pump refill (Time 2 [T2]). For this preliminary sample, collected as part of a larger study protocol, we used a design based on two time-points. To gain insight from those with lived experience, there was routine engagement with the patient and family council of the participating hospital to discuss study design, measurement approaches, and related topics. This council includes adult patients, parents, and family members dedicated to providing input and feedback on research and quality improvement projects within the hospital. Participants. Fourteen children with CP (n=7 male) were included in this initial assessment of CSF analyte levels (mean age = 9 years, 8 months [SD= 2.25] at T1; mean age = 10 years, 10 months [SD = 2.33] at T2). Specific CP diagnoses included: quadriplegia (n=11) and diplegia (n=3). A large proportion of participants were non-ambulatory (Gross Motor Function Classification System [GMFCS] level III [n=1, 7%] and V [n=13, 93%]). Participants identified as Caucasian (n=12, 86%), African American (n=1, 7%), and African (n=1, 7%). Participants were included in the study if they (a) had cerebral palsy, (b) were between 3-21 years of age, and (c) were scheduled for initial ITB pump implant at Gillette Children’s Hospital. Individuals were excluded if (a) they had an existing cerebral shunt; or (b) they had compounded dosing (i.e., opioid adjunctive to baclofen) through their pump. CSF collection. CSF was collected during a standard-of-care surgical procedure (ITB pump implant; T1). In all cases, the surgery proceeded as usual until the spinal catheter had been placed. Then, the neurosurgeon collected 10-20 ml of CSF from the spinal catheter placed well above the spinal puncture site. This method avoided contaminating the collected CSF with blood. After surgery, CSF was collected at baclofen refill visits by aspirating a small amount of CSF directly from the catheter access port (T2). Due to post-surgical swelling, it was unadvisable to attempt to aspirate the port until the second or third baclofen refill after surgery. Time between CSF collections was on average 8 months, 2 weeks (SD=4.4, 2.6-23.0 months). Immediately following collection, the CSF was placed on wet ice (+4 °C) and transported to a cold room for processing, centrifuged at 3000 rpm x 5 minutes, pipetted into 100 µL and 250 µL aliquots, flash frozen in liquid nitrogen and archived at -80°C. Specimen samples were tested by the Cytokine Reference Laboratory (University of Minnesota). This is a CLIA’88-licensed facility (license #24D0931212). Samples were assayed according to manufacturer’s instructions. Fluorescent color-coded beads coated with a specific capture antibody were added to each sample. After incubation and washing, biotinylated detection antibody was added, followed by phycoerythrin-conjugated streptavidin. The beads were read on a Luminex instrument (Bioplex 100). Samples were run in duplicate and values were interpolated from 5 parameter-fitted standard curves. Statistical analyses. While a number of pro- and anti-nociceptive mediators and cytokines were assayed there were missing values for many detected analytes. In some situations, the lower limit of quantification (LLOQ) values or sample standard deviation (SD) could be used to impute missing values; however, the considerable need for imputation in this dataset would have resulted in uncertain outcomes. For purposes of an exploratory study and given the issues with power as well as the high degree of missingness, we proceeded conservatively using only analytes with ≥ 85% data available across all participants and timepoints (T1 and T2) to run paired comparisons without imputing. Paired comparisons resulted in a minimal amount of further data loss as participants were excluded from a comparison if they were missing a T1 or T2 analyte value (see Table 1 for sample size by analyte). Analytes not selected for statistical comparisons had ≤ 61% data available (Supplemental Table 1). Analytes with adequate available data were then evaluated for potential outliers by examining datapoints that fell under the 1st percentile or above the 99th percentile, while also considering distribution of the data, proximity of other data points, and possible sources of analyte level inaccuracy (i.e. sample contamination). Four outlier values were detected (see Table 1 footer). All four outliers originated from two post-surgery CSF samples, one was noted to be contaminated with red blood cells and the other was from the only participant that was ambulatory (GMFCS level III) where all other participants were non-ambulatory (GMFCS level V). Data analysis relied on descriptive statistics to document mean and median analyte levels with SD and interquartile ranges (IQR). Normality of data were assessed using histograms and quantile-quantile (Q-Q) plots. As the data were not normally distributed, Wilcoxon signed-rank tests were used to compare analyte levels from T1 to T2 and calculate effect sizes, r. One-sided tests with the alternative hypothesis of greater were used as we hypothesized and were practically interested in testing for increases in the median analyte values following ITB surgery. Intercorrelations between cytokines at each time point were assessed using spearman correlations using pairwise complete observations for handling missing data. For hypotheses generating purposes, analytes that significantly increased from T1 to T2 were plotted by biological sex for visual inspection. Analyte level difference scores were then calculated and used for comparisons by biological sex, utilizing two-sided Wilcoxon-Mann-Whitney tests. R statistical software was used for all analyses. Results Given our approach described above, the following analytes met criteria and were included for T1-T2 comparisons – noradrenaline, interleukin 1 receptor antagonist (IL-1RA), interleukin 8 (IL-8), interleukin 10 (IL-10), monocyte chemotactic protein (MCP1, MCP2), interferon gamma (IFNG), macrophage inflammatory protein-1 alpha (MIP-1a), vascular endothelial growth factor (VEGF), human cytokine I-309 (I309), and stromal cell-derived factor 1 (SDF-1a). Significant increases from T1 to T2 (p<0.05) were observed for the rank ordered values (pg/ml) for the three interleukins (IL-1RA, IL-8, and IL-10; Figure 1) with medium and large effect sizes (0.44-0.84). Increases in IL-1RA were the most robust from T1 (Md = 38.4, IQR = 16.2) to T2 (Md = 213.6, IQR = 493.6, V = 89, p <.001). See Table 1 for analyte levels and timepoint comparisons. Intercorrelations between cytokines were explored at T1 and T2 with multiple significant correlations observed at each time point (Figure 2). There were no statistically significant differences in sex change scores from T1 to T2 in the three interleukins (p>.05; Supplemental Table 2; Figure 3). Discussion The main preliminary observations seem to point to changes in levels of several molecules from the interleukin family following intrathecal baclofen implant. In general, interleukins regulate immune responses often with pro- and anti-inflammatory properties. Zareen et al. detected altered inflammatory responses in children with CP in a study comparing plasma cytokine levels in 12 children with CP to age-matched controls.[11] Children with CP had elevated erythropoietin levels at baseline and had reduced IL-1α, IL1β, IL-2, and IL-6 inflammatory response to lipopolysaccharide stimulation. The authors noted the hyporesponsiveness may reflect a generalized decreased capacity to produce pro-inflammatory cytokines in response to lipopolysaccharide simulation, at least for some cytokines, and noted that such hyporesponsiveness could have consequences for health in daily life (e.g., response to infections and vaccines).[11, 12] The current study assessed different interleukins and in CSF rather than plasma but detected changes in interleukin levels post-surgery in children with CP. The variation in elapsed time between T1 and T2 CSF collection, while unavoidable due to patient differences in appropriate timing for ITB pump refill, may have introduced additional variability in analyte levels. As there are no available referent values, comparisons are not normative but rather use within subject logic build around comparisons between timepoints; however, such an approach provides advantages for translational research purposes. This study was exploratory and based on a small nonrandom clinical convenience sample, as such, the conclusions made are specific to this sample. Below, we describe and discuss relevant prior clinical work from within the interleukin family related to pain sensitivity and surgical and functional outcomes. The consideration of other reported observations in relation to ours is made based on logical generalization from similar work (CSF measurement of cytokines) from clinical samples with known or suspected pain and/or neurodevelopmental issues and is done for hypothesis generating purposes. IL-10 is an anti-inflammatory cytokine that inhibits the activation of immune cells and the production of pro-inflammatory factors with emerging but limited clinically relevant evidence implicating it is associated with inflammatory response, chronic pain, and neurodevelopmental outcome. IL-10 plays a crucial role in inflammatory pain resolution and increased IL-10 in males was associated with faster pain resolution.[10] Increased CSF IL-10 is shown to be a negative prognostic candidate marker/factor after traumatic brain injury.[13] Specific to early neurodevelopmental outcomes, in a study to identify candidate biomarkers in CSF associated with neonatal encephalopathy, CSF IL-10 was inversely related to cognitive and motor outcome.[14] Finally, compared to preoperative levels, CSF concentrations of IL-10 were increased after orthopedic surgery in severe osteoarthritis, possibly associated with decreased pain sensitivity.[15] In our sample, mean CSF IL-10 concentration values increased following ITB implant. IL-8is a proinflammatory cytokine also with clinical evidence, albeit limited, relevant to inflammation, pain, and neurodevelopmental outcome. Specific empirical examples include data showing a significant increase in CSF IL-8 in children with non-obstructive hydrocephalus and obstructive posthemorrhagic hydrocephalus.[16] Bjurstrom et al[15] did not find CSF concentration changes in IL-8 before and after hip arthroplasty but did report increases in plasma IL-8 after orthopedic surgery in severe osteoarthritis, possibly associated with decreased pain sensitivity. There were also observations made by Giron, et al[17] of increased, on average, IL-8 CSF levels in a small group of chronic pain patients/postlaminectomy syndrome compared to control. In our sample, IL-8 CSF concentration values were also increased after ITB pump implant procedure. Last, IL-1RAis a member of the IL-1 family and associated with innate immunity/inflammation. IL-1RA is an endogenous antagonist of the IL-1 receptor and blocks the pro-inflammatory effects of IL-1α and β and thereby regulates production and activity on IL-1. It is implicated in pain with clinical evidence showing a modest increase in CSF levels from patients with headache.[18] IL-1 has been shown to be a key mediator in rheumatoid arthritis, an autoimmune disease, and recombinant IL-1RA is in pharmacological use, Anakinra, in the treatment of rheumatoid arthritis.[19] In our sample there was a large increase in CSF IL-1RA levels following ITB implant. While underpowered to detect significant differences, the visually observed sex differences following ITB pump implant warrant discussion and further investigation in CP. Sim et al. also found males had significantly increased cutaneous IL-10 at 72 hours, 8 weeks, and 3 months after a traumatic pain exposure (motor vehicle accident) compared to females.[10] Increased IL-10 was associated with faster pain resolution. Upon visual inspection, males in this sample had a greater increase in IL-10 after surgery. Studies have found sex differences in IL-1RA, including an IL-1RA gene polymorphism, leading to females producing more IL-1RA.[20] Such sex differences may be a factor influencing inflammatory responses, and pain perception.[20] Visually, females in the current sample had a greater increase in IL-1RA after surgery compared to males. In adults with osteoarthritis, Kosek et al.[21] found females had increased synovial fluid IL-8 levels, compared to males, but found no sex differences in CSF or plasma IL-8. Zhao et al.[22] found females with mild traumatic brain injury had increased serum IL-8 compared to males. Hussein et al. found sex differences in CSF IL-8 levels in newborns. Newborn females considered to have experienced asphyxiation during birth had significantly higher IL-8 levels compared to healthy newborn females and healthy and asphyxiated males.[23] In the current sample, males appeared visually to have an increased level of CSF IL-8 following surgery. There is evidence that IL-8 blocks neutrophil infiltration to the site of inflammation,[24] has protective effects during injury,[24] and promotes tissue remodeling.[25] Sex differences in inflammatory biomarkers have generally aligned with observations that males are more vulnerable than females to brain injuries occurring at birth.[26] As prematurity and asphyxiation are among the most common etiologies for CP and chronic pain conditions and surgeries are frequent for those with CP, examining sex and patient-specific differences potentially involved in neuroimmune signaling in CP could be particularly valuable. Overall, our observations of increased CSF IL-10 and IL-8 following ITB pump implant are consistent with Bjurstrom and Giron’s observations of increases post-procedure [15]and some limited observations of IL-1RA elevations in chronic pain (headache).[17]Given other independent observations of altered inflammatory response profiles in children with CP[11, 27] and our findings of birth status in relation to inflammatory biomarker profile differences in CP,[28] further work seems warranted to understand adaptive immunity response profiles in CP in relation to chronic pain and in relation to treatments with pain outcome implications. Doing so could help clarify whether there are biomarkers that might help predict pain treatment outcomes in a highly vulnerable pediatric population at high risk for chronic pain being underrecognized and undertreated. Abbreviations CP cerebral palsy ITB intrathecal baclofen CSF cerebral spinal fluid T1 Time 1, during surgery T2 Time 2, After surgery LLOQ Lower limit of quantification M Mean SD Standard Deviation GMFCS Gross Motor Function Classification System IQR interquartile ranges Q-Q quantile-quantile IL1RA Interleukin 1 receptor antagonist IL-8 interleukin 8 IL-10 interleukin 10 MCP1 monocyte chemotactic protein 1 MCP2 monocyte chemotactic protein 2 IFNG interferon gamma MIP-1a macrophage inflammatory protein-1 alpha VEGF vascular endothelial growth factor I-309 human cytokine I-309 SDF-1a stromal cell-derived factor 1 ITB intrathecal baclofen IL-1α interleukin 1 alpha IL1β interleukin beta IL-2 interleukin 1 IL-6 interleukin 6 Md Median SD Standard Deviation Declarations Ethics approval and consent to participate: All human subjects’ requirements were met, and the study was approved by the Protection for Human Subjects Committee of the University of Minnesota. Written informed consent was obtained from each child’s parent or legal representative. Assent to participate was obtained from each child over the age of eight who was cognitively able to understand the materials in simplified language. All aspects of this research study adhered to the ethical principles of the Declaration of Helsinki. Consent for publication: Not applicable. Availability of data and materials: Deidentified individual participant data and data dictionaries will be made available upon publication to researchers who provide a methodologically sound proposal for use of these data. Proposals should be submitted to the corresponding author. Competing interests: The authors declare that they have no competing interests. Funding: This work was supported, in part, by Eunice Kennedy Shriver NICHD Grant No. 69985, Helse Sør-Øst RHF Grant no. 2022096, and Gillette Children’s Hospital Foundation. Author Contributions: FS conceptualized and designed the study, drafted the initial manuscript, and oversaw data collection and data analyses. ASK assisted in manuscript writing and editing. MW assisted in data analyses, manuscript writing, and data visualization. JS provided clinical guidance on study design and feasibility and supported the clinical collection of cerebral spinal fluid samples. ME and APM collaborated on study methodology, assayed the cerebral spinal fluid samples, and supported interpretation and manuscript writing. DD created a data analyses plan and conducted initial data analyses with interpretation. CB collaborated on study methodology, assisted with manuscript writing and editing, provided guidance on data analyses and data visualization. All authors read and approved the final manuscript. The authors agree to be accountable for the work presented. Acknowledgements: The authors appreciate the time and support of the children and families who took part in this study. The authors acknowledge the efforts of the neurosurgeons and nurse practitioners who acquired cerebral spinal fluid samples for this study. References McIntyre S, Goldsmith S, Webb A, Ehlinger V, Hollung SJ, McConnell K, Arnaud C, Smithers-Sheedy H, Oskoui M, Khandaker G et al : Global prevalence of cerebral palsy: A systematic analysis . Dev Med Child Neurol 2022, 64 (12):1494-1506. Barney CC, Merbler AM, Stansbury J, Krach LE, Partington M, Graupman P, Kim PD, Song D, Symons FJ: Musculoskeletal Pain Outcomes Pre- and Post Intrathecal Baclofen Pump Implant in Children With Cerebral Palsy: A Prospective Cohort Study . Arch Rehabil Res Clin Transl 2020, 2 (2):100049. Foran JR, Steinman S, Barash I, Chambers HG, Lieber RL: Structural and mechanical alterations in spastic skeletal muscle . Dev Med Child Neurol 2005, 47 (10):713-717. 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Kosek E, Finn A, Ultenius C, Hugo A, Svensson C, Ahmed AS: Differences in neuroimmune signalling between male and female patients suffering from knee osteoarthritis . J Neuroimmunol 2018, 321 :49-60. Zhao P, Zhu P, Zhang D, Yin B, Wang Y, Hussein NM, Yan Z, Liu X, Bai G: Sex Differences in Cerebral Blood Flow and Serum Inflammatory Cytokines and Their Relationships in Mild Traumatic Brain Injury . Front Neurol 2021, 12 :755152. Hussein MH, Daoud GA, Kakita H, Hattori A, Murai H, Yasuda M, Mizuno K, Goto K, Ozaki Y, Ito T et al : The sex differences of cerebrospinal fluid levels of interleukin 8 and antioxidants in asphyxiated newborns . Shock 2007, 28 (2):154-159. Simonet WS, Hughes TM, Nguyen HQ, Trebasky LD, Danilenko DM, Medlock ES: Long-term impaired neutrophil migration in mice overexpressing human interleukin-8 . J Clin Invest 1994, 94 (3):1310-1319. Li A, Dubey S, Varney ML, Dave BJ, Singh RK: IL-8 directly enhanced endothelial cell survival, proliferation, and matrix metalloproteinases production and regulated angiogenesis . J Immunol 2003, 170 (6):3369-3376. Lauterbach MD, Raz S, Sander CJ: Neonatal hypoxic risk in preterm birth infants: the influence of sex and severity of respiratory distress on cognitive recovery . Neuropsychology 2001, 15 (3):411-420. Lin CY, Chang YC, Wang ST, Lee TY, Lin CF, Huang CC: Altered inflammatory responses in preterm children with cerebral palsy . Ann Neurol 2010, 68 (2):204-212. Goracke-Postle CJ, Burkitt CC, Panoskaltsis-Mortari A, Ehrhardt M, Wilcox GL, Graupman P, Partington M, Symons FJ: Expression of and correlational patterns among neuroinflammatory, neuropeptide, and neuroendocrine molecules from cerebrospinal fluid in cerebral palsy . BMC Neurol 2021, 21 (1):384. Tables Table 1. Means, medians, and one-sided non-parametric comparisons of analyte levels in cerebral spinal fluid for children with cerebral palsy collected during intrathecal baclofen pump implant surgery (T1) and at ITB pump refill visits (T2). Analyte % values available for analyses (n=) T1 Mean (SD) pg/mL T2 Mean (SD) pg/mL T1 Median (IQR) pg/mL T2 Median (IQR) pg/mL Median Difference V p Effect size, r Noradrenaline 100% (n=14) 2.01 (1.42) 2.24 (1.26) 1.58 (1.47) 2 (1.64) 0.42 58 0.377 0.092 IL-1RA 92.9% (n=13)* 56.19 (47.98) 343.16 (323.88) 38.4 (16.2) 213.6 (493.6) 175.2 89 <.001 0.843 IL-8 92.9% (n=13)* 27.89 (12.34) 49.69 (29.75) 23.5 (16.2) 39.7 (49.5) 16.2 76 0.016 0.591 IL-10 92.9% (n=13)* 0.68 (0.09) 0.92 (0.53) 0.7 (0.1) 0.7 (0.3) 0 30 0.049 0.444 MCP-1 92.9% (n=13)* 312.93 (87.48) 332.27 (128.09) 336.5 (123.6) 305.4 (66.5) -31.1 51 0.368 0.107 MCP-2 78.6% (n=11) 5.78 (3.12) 6.04 (4.45) 5.4 (1.4) 4.6 (1.35) -0.8 29.5 0.639 0.094 IFNg 78.6% (n=11) 3.4 (2.92) 2.05 (1.57) 1.6 (4.5) 1.3 (1.25) -0.3 18 0.916 0.403 MIP-1a 85.7% (n=12) 62.41 (45.15) 67.14 (63.17) 51.1 (37.88) 47.3 (16.48) -3.8 37 0.378 0.102 VEGF 100% (n=14) 2.41 (0.83) 4.16 (4.46) 2.35 (0.48) 2.8 (1.47) 0.45 65.5 0.216 0.218 I-309 78.6% (n=11) 1.15 (0.74) 1.63 (1.89) 1.1 (0.85) 1.1 (0.8) 0 28.5 0.257 0.243 SDF-1a 100% (n=14) 363.25 (242.33) 284.23 (253.01) 274.65 (214.48) 189.6 (72.25) -85.05 24 0.938 0.420 *IL-1RA: Post outlier value of >5050 removed; *IL-8: Post outlier value of 497.4 removed; *IL-10: Post outlier value of 5.5 removed; *MCP-1: Post outlier value of 1435.4 removed. Additional Declarations No competing interests reported. Supplementary Files SymonsSupplementalTable1.docx SymonsSupplementalTable2.docx Cite Share Download PDF Status: Under Review Version 1 posted Reviews received at journal 25 Nov, 2025 Reviews received at journal 19 Nov, 2025 Reviews received at journal 17 Nov, 2025 Reviews received at journal 17 Nov, 2025 Reviewers agreed at journal 14 Nov, 2025 Reviews received at journal 13 Nov, 2025 Reviewers agreed at journal 13 Nov, 2025 Reviews received at journal 12 Nov, 2025 Reviewers agreed at journal 12 Nov, 2025 Reviews received at journal 11 Nov, 2025 Reviewers agreed at journal 10 Nov, 2025 Reviewers agreed at journal 10 Nov, 2025 Reviewers agreed at journal 10 Nov, 2025 Reviewers agreed at journal 09 Nov, 2025 Reviewers agreed at journal 09 Nov, 2025 Reviewers agreed at journal 09 Nov, 2025 Reviewers invited by journal 31 Oct, 2025 Editor assigned by journal 24 Aug, 2025 Editor invited by journal 22 Aug, 2025 Submission checks completed at journal 20 Aug, 2025 First submitted to journal 20 Aug, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7277982","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":543428573,"identity":"0db8f9c9-50e4-4fd1-8454-37287079893e","order_by":0,"name":"Frank J Symons","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAvklEQVRIiWNgGAWjYNACA4n6fgiLmVgtFTaMMxtI03ImjXHDAWK1yM/ITnxc2HaY2fhGdtoDhgrrxAZCWgxu5G42ntl2mM3sRu52A4Yz6URokcjdJs3bdpgHqGWbBGPbYcJa5GdAtEgYzwBp+UeEFgag4dI8Z9IMQNZJMDYQocXgzNvNxjwVNgkSZ95uk0g4lm5M2GHtuRsf8xhIJPC3A235UGMtS9hhAglInAQcilAB/wGilI2CUTAKRsFIBgDPID9ukI5vrQAAAABJRU5ErkJggg==","orcid":"","institution":"University of Minnesota","correspondingAuthor":true,"prefix":"","firstName":"Frank","middleName":"J","lastName":"Symons","suffix":""},{"id":543428574,"identity":"09bfbf21-05ac-429f-b3b9-5472f7d556e2","order_by":1,"name":"Annette Steen-Hansen Krøglid","email":"","orcid":"","institution":"Vestfold Hospital Trust","correspondingAuthor":false,"prefix":"","firstName":"Annette","middleName":"Steen-Hansen","lastName":"Krøglid","suffix":""},{"id":543428575,"identity":"869e0b63-22af-416a-b5a6-d724fa3cf0ba","order_by":2,"name":"Maykala 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1","display":"","copyAsset":false,"role":"figure","size":46755,"visible":true,"origin":"","legend":"\u003cp\u003eCerebral spinal fluid analyte levels for children with cerebral palsy collected during intrathecal baclofen (ITB) pump implant surgery (T1) and at ITB pump refill visits (T2) for interleukin 1 receptor antagonist (IL-1RA), interleukin 8 (IL-8), and interleukin 10 (IL-10). All comparisons p \u0026lt; .05.\u003c/p\u003e","description":"","filename":"SymonsFigure1.png","url":"https://assets-eu.researchsquare.com/files/rs-7277982/v1/91290b6f3e2886da663cbfc3.png"},{"id":95805982,"identity":"d9863ba2-57db-4ecd-b1a2-90b2ab8447bc","added_by":"auto","created_at":"2025-11-13 08:47:11","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":991239,"visible":true,"origin":"","legend":"\u003cp\u003eAnalyte correlation plots for cerebral spinal fluid collected during intrathecal baclofen (ITB) pump implant surgery (T1) and at ITB pump refill visits (T2) for children with cerebral palsy. * p \u0026lt; .05, ** p \u0026lt;.01, *** p = .001.\u003c/p\u003e","description":"","filename":"SymonsFigure2.png","url":"https://assets-eu.researchsquare.com/files/rs-7277982/v1/2689a716516772b88b6e99e1.png"},{"id":95806258,"identity":"ef0795fa-d243-4caf-97f6-b18233d7f116","added_by":"auto","created_at":"2025-11-13 08:47:21","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":49009,"visible":true,"origin":"","legend":"\u003cp\u003eCerebral spinal fluid analyte levels for children with cerebral palsy collected during intrathecal baclofen (ITB) pump implant surgery (T1) and at ITB pump refill visits (T2) stratified by biological sex for interleukin 1 receptor antagonist (IL-1RA), interleukin 8 (IL-8), and interleukin 10 (IL-10). All comparisons p \u0026gt; .05.\u003c/p\u003e","description":"","filename":"SymonsFigure3.png","url":"https://assets-eu.researchsquare.com/files/rs-7277982/v1/0bab8a911805e4187dd10a3e.png"},{"id":95810309,"identity":"83541638-37a6-47b8-9111-d46ac264e102","added_by":"auto","created_at":"2025-11-13 08:52:18","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2814800,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7277982/v1/2eaaa998-46ee-4c0b-a3e7-9e3598f7664f.pdf"},{"id":95806386,"identity":"b4cd6350-3cce-4086-acf5-8b39d5528443","added_by":"auto","created_at":"2025-11-13 08:47:27","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":18861,"visible":true,"origin":"","legend":"","description":"","filename":"SymonsSupplementalTable1.docx","url":"https://assets-eu.researchsquare.com/files/rs-7277982/v1/6ef1af78b51415a9463763ad.docx"},{"id":95806449,"identity":"fb097e88-03f2-4d21-9132-5fa22e14018a","added_by":"auto","created_at":"2025-11-13 08:47:31","extension":"docx","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":18508,"visible":true,"origin":"","legend":"","description":"","filename":"SymonsSupplementalTable2.docx","url":"https://assets-eu.researchsquare.com/files/rs-7277982/v1/d29d72a9ce17515dd2d854fb.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"An exploratory investigation of neuroinflammatory and nociceptive biomarkers from cerebrospinal fluid in children with cerebral palsy following intrathecal baclofen pump implant surgery","fulltext":[{"header":"Introduction","content":"\u003cp\u003eCerebral Palsy (CP) is the most common congenital cause of disability in children affecting approximately 2/1000 live births depending on global region.[1] Spasticity is reported in approximately 80% of those with CP and, depending on severity, results in chronic pain and interferes with function and comfort. Intrathecal baclofen (ITB) is regarded as relatively effective in the reduction of spasticity and is frequently used to treat hypertonicity associated with CP. Although almost all studies report changes in muscle tone, the evidence for other outcomes including pain reduction is less clear and often there are individuals for whom pain persists, but this is not well understood mechanistically.[2]\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eIn contrast to cutaneous pain, much less is known about the origins and mechanisms of spasticity-related muscle pain.[3] Some experimental models based on inflammation (injection of hypertonic saline, carrageenan) show that inflammatory mediators (bradykinin, serotonin, prostaglandin) released after muscle damage, sensitize muscle nociceptors by site-specific binding.[4] Muscle pain that is the product of chronic spasticity may not spontaneously resolve and may become persistent and, in this sense, pathological. It could, therefore, be the case that the initial local ischemia from sustained muscle fiber contraction has several potential deleterious \u0026lsquo;downstream\u0026rsquo; effects including pathophysiological inflammatory and nociceptive consequences affecting excitatory or inhibitory circuits peripherally but also centrally.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThere is also an emerging viewpoint on the role of central neuro-inflammation consistent with documented early white matter damage leading to CP and, from our perspective, this is a possible pathophysiological contributor to the biology of chronic pain mechanisms in CP.[5] Children with CP routinely undergo more surgeries compared to their peers, which in other samples and models, has typically been associated with pronounced increases in inflammatory biomarkers.[6-8] These inflammatory increases have predicted important postoperative outcomes, such as time to healing and cognitive decline; outcomes potentially of particular value in CP given the associated sequelae and medical needs.[6, 9, 10]\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eIn this exploratory study we assessed nociceptive- and inflammatory-relevant molecules in cerebral spinal fluid (CSF) from a convenience sample of children with CP being treated for spasticity through standard-of-care ITB implant surgery for hypothesis-generating research purposes. The primary aim of this study was to investigate whether levels of nociceptive- and inflammatory-relevant molecules increased following ITB implant surgery. The secondary aim of this study was to investigate potential intercorrelations in CSF cytokines at each time point. \u0026nbsp;\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003eThis study was conducted in accordance with the ethical principles of the Declaration of Helsinki and approved by the Institutional Review Board of the University of Minnesota. Clinical trial number: not applicable. Written informed consent was obtained from each child’s parent or legal representative. Assent to participate was obtained from each child over the age of eight who was cognitively able to understand the materials in simplified language. A clinical convenience sample was formed for a molecular biomarker measurement during ITB pump implant surgery (Time 1 [T1]) and after surgery during baclofen pump refill (Time 2 [T2]). For this preliminary sample, collected as part of a larger study protocol, we used a design based on two time-points. To gain insight from those with lived experience, there was routine engagement with the patient and family council of the participating hospital to discuss study design, measurement approaches, and related topics. This council includes adult patients, parents, and family members dedicated to providing input and feedback on research and quality improvement projects within the hospital.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eParticipants.\u003c/em\u003e Fourteen children with CP (n=7 male) were included in this initial assessment of CSF analyte levels (mean age = 9 years, 8 months [SD= 2.25] at T1; mean age = 10 years, 10 months [SD = 2.33] at T2). Specific CP diagnoses included: quadriplegia (n=11) and diplegia (n=3). A large proportion of participants were non-ambulatory (Gross Motor Function Classification System [GMFCS] level III [n=1, 7%] and V [n=13, 93%]). Participants identified as Caucasian (n=12, 86%), African American (n=1, 7%), and African (n=1, 7%). Participants were included in the study if they (a) had cerebral palsy, (b) were between 3-21 years of age, and (c) were scheduled for initial ITB pump implant at Gillette Children’s Hospital. Individuals were excluded if (a) they had an existing cerebral shunt; or (b) they had compounded dosing (i.e., opioid adjunctive to baclofen) through their pump.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eCSF collection.\u0026nbsp;\u003c/em\u003eCSF was collected during a standard-of-care surgical procedure (ITB pump implant; T1). In all cases, the surgery proceeded as usual until the spinal catheter had been placed. Then, the neurosurgeon collected 10-20 ml of CSF from the spinal catheter placed well above the spinal puncture site. This method avoided contaminating the collected CSF with blood. After surgery, CSF was collected at baclofen refill visits by aspirating a small amount of CSF directly from the catheter access port (T2). Due to post-surgical swelling, it was unadvisable to attempt to aspirate the port until the second or third baclofen refill after surgery. Time between CSF collections was on average 8 months, 2 weeks (SD=4.4, 2.6-23.0 months). Immediately following collection, the CSF was placed on wet ice (+4 °C) and transported to a cold room for processing, centrifuged at 3000 rpm x 5 minutes, pipetted into 100 µL and 250 µL aliquots, flash frozen in liquid nitrogen and archived at -80°C.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eSpecimen samples were tested by the Cytokine Reference Laboratory (University of Minnesota). This is a CLIA’88-licensed facility (license #24D0931212). Samples were assayed according to manufacturer’s instructions. Fluorescent color-coded beads coated with a specific capture antibody were added to each sample. After incubation and washing, biotinylated detection antibody was added, followed by phycoerythrin-conjugated streptavidin. The beads were read on a Luminex instrument (Bioplex 100). Samples were run in duplicate and values were interpolated from 5 parameter-fitted standard curves.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eStatistical analyses.\u003c/em\u003e While a number of pro- and anti-nociceptive mediators and cytokines were assayed there were missing values for many detected analytes. In some situations, the lower limit of quantification (LLOQ) values or sample standard deviation (SD) could be used to impute missing values; however, the considerable need for imputation in this dataset would have resulted in uncertain outcomes. For purposes of an exploratory study and given the issues with power as well as the high degree of missingness, we proceeded conservatively using only analytes with ≥ 85% data available across all participants and timepoints (T1 and T2) to run paired comparisons without imputing. Paired comparisons resulted in a minimal amount of further data loss as participants were excluded from a comparison if they were missing a T1 or T2 analyte value (see Table 1 for sample size by analyte). Analytes not selected for statistical comparisons had ≤ 61% data available (Supplemental Table 1). Analytes with adequate available data were then evaluated for potential outliers by examining datapoints that fell under the 1st percentile or above the 99th percentile, while also considering distribution of the data, proximity of other data points, and possible sources of analyte level inaccuracy (i.e. sample contamination). Four outlier values were detected (see Table 1 footer). All four outliers originated from two post-surgery CSF samples, one was noted to be contaminated with red blood cells and the other was from the only participant that was ambulatory (GMFCS level III) where all other participants were non-ambulatory (GMFCS level V). \u0026nbsp;\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eData analysis relied on descriptive statistics to document mean and median analyte levels with SD and interquartile ranges (IQR). Normality of data were assessed using histograms and quantile-quantile (Q-Q) plots. As the data were not normally distributed, Wilcoxon signed-rank tests were used to compare analyte levels from T1 to T2 and calculate effect sizes, r. One-sided tests with the alternative hypothesis of greater were used as we hypothesized and were practically interested in testing for increases in the median analyte values following ITB surgery. Intercorrelations between cytokines at each time point were assessed using spearman correlations using pairwise complete observations for handling missing data. For hypotheses generating purposes, analytes that significantly increased from T1 to T2 were plotted by biological sex for visual inspection. Analyte level difference scores were then calculated and used for comparisons by biological sex, utilizing two-sided Wilcoxon-Mann-Whitney tests. R statistical software was used for all analyses.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eGiven our approach described above, the following analytes met criteria and were included for T1-T2 comparisons – noradrenaline, interleukin 1 receptor antagonist (IL-1RA),\u0026nbsp;interleukin 8 (IL-8), interleukin 10 (IL-10), monocyte chemotactic protein (MCP1, MCP2), interferon gamma (IFNG), macrophage inflammatory protein-1 alpha (MIP-1a), vascular endothelial growth factor (VEGF), human cytokine I-309 (I309), and stromal cell-derived factor 1 (SDF-1a). Significant increases from T1 to T2 (p\u0026lt;0.05) were observed for the rank ordered values (pg/ml) for the three interleukins (IL-1RA, IL-8, and IL-10; Figure 1) with medium and large effect sizes (0.44-0.84). Increases in IL-1RA were the most robust from T1 (Md = 38.4, IQR = 16.2) to T2 (Md = 213.6, IQR = 493.6, \u003cem\u003eV\u003c/em\u003e = 89, \u003cem\u003ep\u003c/em\u003e\u0026lt;.001). See Table 1 for analyte levels and timepoint comparisons. Intercorrelations between cytokines were explored at T1 and T2 with multiple significant correlations observed at each time point (Figure 2). There were no statistically significant differences in sex change scores from T1 to T2 in the three interleukins (p\u0026gt;.05; Supplemental Table 2; Figure 3).\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThe main preliminary observations seem to point to changes in levels of several molecules from the interleukin family following intrathecal baclofen implant. In general, interleukins regulate immune responses often with pro- and anti-inflammatory properties. Zareen et al. detected altered inflammatory responses in children with CP in a study comparing plasma cytokine levels in 12 children with CP to age-matched controls.[11] Children with CP had elevated erythropoietin levels at baseline and had reduced IL-1α, IL1β, IL-2, and IL-6 inflammatory response to lipopolysaccharide stimulation. The authors noted the hyporesponsiveness may reflect a generalized decreased capacity to produce pro-inflammatory cytokines in response to lipopolysaccharide simulation, at least for some cytokines, and noted that such hyporesponsiveness could have consequences for health in daily life (e.g., response to infections and vaccines).[11, 12] The current study assessed different interleukins and in CSF rather than plasma but detected changes in interleukin levels post-surgery in children with CP.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe variation in elapsed time between T1 and T2 CSF collection, while unavoidable due to patient differences in appropriate timing for ITB pump refill, may have introduced additional variability in analyte levels. As there are no available referent values, comparisons are not normative but rather use within subject logic build around comparisons between timepoints; however, such an approach provides advantages for translational research purposes. This study was exploratory and based on a small nonrandom clinical convenience sample, as such, the conclusions made are specific to this sample. Below, we describe and discuss relevant prior clinical work from within the interleukin family related to pain sensitivity and surgical and functional outcomes. The consideration of other reported observations in relation to ours is made based on logical generalization from similar work (CSF measurement of cytokines) from clinical samples with known or suspected pain and/or neurodevelopmental issues and is done for hypothesis generating purposes.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eIL-10 is an anti-inflammatory cytokine that inhibits the activation of immune cells and the production of pro-inflammatory factors with emerging but limited clinically relevant evidence implicating it is associated with inflammatory response, chronic pain, and neurodevelopmental outcome. IL-10 plays a crucial role in inflammatory pain resolution and increased IL-10 in males was associated with faster pain resolution.[10] Increased CSF IL-10 is shown to be a negative prognostic candidate marker/factor after traumatic brain injury.[13] Specific to early neurodevelopmental outcomes, in a study to identify candidate biomarkers in CSF associated with neonatal encephalopathy, CSF IL-10 was inversely related to cognitive and motor outcome.[14] Finally, compared to preoperative levels, CSF concentrations of IL-10 were increased after orthopedic surgery in severe osteoarthritis, possibly associated with decreased pain sensitivity.[15] In our sample, mean CSF IL-10 concentration values increased following ITB implant.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eIL-8is a proinflammatory cytokine also with clinical evidence, albeit limited, relevant to inflammation, pain, and neurodevelopmental outcome. Specific empirical examples include data showing a significant increase in CSF IL-8 in children with non-obstructive hydrocephalus and obstructive posthemorrhagic hydrocephalus.[16] Bjurstrom et al[15] did not find CSF concentration changes in IL-8 before and after hip arthroplasty but did report increases in plasma IL-8 after orthopedic surgery in severe osteoarthritis, possibly associated with decreased pain sensitivity. There were also observations made by Giron, et al[17] of increased, on average, IL-8 CSF levels in a small group of chronic pain patients/postlaminectomy syndrome compared to control. In our sample, IL-8 CSF concentration values were also increased after ITB pump implant procedure.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eLast, IL-1RAis a member of the IL-1 family and associated with innate immunity/inflammation. IL-1RA is an endogenous antagonist of the IL-1 receptor and blocks the pro-inflammatory effects of IL-1α and β and thereby regulates production and activity on IL-1. It is implicated in pain with clinical evidence showing a modest increase in CSF levels from patients with headache.[18] IL-1 has been shown to be a key mediator in rheumatoid arthritis, an autoimmune disease, and recombinant IL-1RA is in pharmacological use, Anakinra, in the treatment of rheumatoid arthritis.[19] In our sample there was a large increase in CSF IL-1RA levels following ITB implant.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eWhile underpowered to detect significant differences, the visually observed sex differences following ITB pump implant warrant discussion and further investigation in CP. Sim et al. also found males had significantly increased cutaneous IL-10 at 72 hours, 8 weeks, and 3 months after a traumatic pain exposure (motor vehicle accident) compared to females.[10] Increased IL-10 was associated with faster pain resolution. Upon visual inspection, males in this sample had a greater increase in IL-10 after surgery. Studies have found sex differences in IL-1RA, including an IL-1RA gene polymorphism, leading to females producing more IL-1RA.[20] Such sex differences may be a factor influencing inflammatory responses, and pain perception.[20] Visually, females in the current sample had a greater increase in IL-1RA after surgery compared to males.\u003c/p\u003e\n\u003cp\u003eIn adults with osteoarthritis, Kosek et al.[21] found females had increased synovial fluid IL-8 levels, compared to males, but found no sex differences in CSF or plasma IL-8. Zhao et al.[22] found females with mild traumatic brain injury had increased serum IL-8 compared to males. Hussein et al. found sex differences in CSF IL-8 levels in newborns. Newborn females considered to have experienced asphyxiation during birth had significantly higher IL-8 levels compared to healthy newborn females and healthy and asphyxiated males.[23] In the current sample, males appeared visually to have an increased level of CSF IL-8 following surgery. There is evidence that IL-8 blocks neutrophil infiltration to the site of inflammation,[24] has protective effects during injury,[24] and promotes tissue remodeling.[25] Sex differences in inflammatory biomarkers have generally aligned with observations that males are more vulnerable than females to brain injuries occurring at birth.[26] As prematurity and asphyxiation are among the most common etiologies for CP and chronic pain conditions and surgeries are frequent for those with CP, examining sex and patient-specific differences potentially involved in neuroimmune signaling in CP could be particularly valuable.\u003c/p\u003e\n\u003cp\u003eOverall, our observations of increased CSF IL-10 and IL-8 following ITB pump implant are consistent with Bjurstrom and Giron’s observations of increases post-procedure [15]and some limited observations of IL-1RA elevations in chronic pain (headache).[17]Given other independent observations of altered inflammatory response profiles in children with CP[11, 27] and our findings of birth status in relation to inflammatory biomarker profile differences in CP,[28] further work seems warranted to understand adaptive immunity response profiles in CP in relation to chronic pain and in relation to treatments with pain outcome implications. Doing so could help clarify whether there are biomarkers that might help predict pain treatment outcomes in a highly vulnerable pediatric population at high risk for chronic pain being underrecognized and undertreated.\u0026nbsp;\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eCP\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003ecerebral palsy\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eITB\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eintrathecal baclofen\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eCSF\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003ecerebral spinal fluid\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eT1\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eTime 1, during surgery\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eT2\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eTime 2, After surgery\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eLLOQ\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eLower limit of quantification\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eM\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eMean\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eSD\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eStandard Deviation\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eGMFCS\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eGross Motor Function Classification System\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eIQR\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003einterquartile ranges\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eQ-Q\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003equantile-quantile\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eIL1RA\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eInterleukin 1 receptor antagonist\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eIL-8\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003einterleukin 8\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eIL-10\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003einterleukin 10\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eMCP1\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003emonocyte chemotactic protein 1\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eMCP2\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003emonocyte chemotactic protein 2\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eIFNG\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003einterferon gamma\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eMIP-1a\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003emacrophage inflammatory protein-1 alpha\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eVEGF\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003evascular endothelial growth factor\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eI-309\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003ehuman cytokine I-309\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eSDF-1a\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003estromal cell-derived factor 1\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eITB\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eintrathecal baclofen\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eIL-1α\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003einterleukin 1 alpha\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eIL1β\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003einterleukin beta\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eIL-2\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003einterleukin 1\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eIL-6\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003einterleukin 6\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eMd\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eMedian\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003eSD\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eStandard Deviation\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate:\u003c/strong\u003e All human subjects’ requirements were met, and the study was approved by the Protection for Human Subjects Committee of the University of Minnesota. Written informed consent was obtained from each child’s parent or legal representative. Assent to participate was obtained from each child over the age of eight who was cognitively able to understand the materials in simplified language. All aspects of this research study adhered to the ethical principles of the Declaration of Helsinki.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication:\u0026nbsp;\u003c/strong\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials:\u003c/strong\u003e Deidentified individual participant data and data dictionaries will be made available upon publication to researchers who provide a methodologically sound proposal for use of these data. Proposals should be submitted to the corresponding author.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests:\u003c/strong\u003e The authors declare that they have no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding:\u003c/strong\u003e This work was supported, in part, by Eunice Kennedy Shriver NICHD Grant No. 69985, Helse Sør-Øst RHF Grant no. 2022096, and Gillette Children’s Hospital Foundation.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor Contributions:\u003c/strong\u003e FS conceptualized and designed the study, drafted the initial manuscript, and oversaw data collection and data analyses. ASK assisted in manuscript writing and editing. MW assisted in data analyses, manuscript writing, and data visualization. JS provided clinical guidance on study design and feasibility and supported the clinical collection of cerebral spinal fluid samples. ME and APM collaborated on study methodology, assayed the cerebral spinal fluid samples, and supported interpretation and manuscript writing. DD created a data analyses plan and conducted initial data analyses with interpretation. CB collaborated on study methodology, assisted with manuscript writing and editing, provided guidance on data analyses and data visualization. All authors read and approved the final manuscript. The authors agree to be accountable for the work presented.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements:\u003c/strong\u003e The authors appreciate the time and support of the children and families who took part in this study. The authors acknowledge the efforts of the neurosurgeons and nurse practitioners who acquired cerebral spinal fluid samples for this study.\u0026nbsp;\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eMcIntyre S, Goldsmith S, Webb A, Ehlinger V, Hollung SJ, McConnell K, Arnaud C, Smithers-Sheedy H, Oskoui M, Khandaker G\u003cem\u003e et al\u003c/em\u003e: \u003cstrong\u003eGlobal prevalence of cerebral palsy: A systematic analysis\u003c/strong\u003e. \u003cem\u003eDev Med Child Neurol \u003c/em\u003e2022, \u003cstrong\u003e64\u003c/strong\u003e(12):1494-1506.\u003c/li\u003e\n\u003cli\u003eBarney CC, Merbler AM, Stansbury J, Krach LE, Partington M, Graupman P, Kim PD, Song D, Symons FJ: \u003cstrong\u003eMusculoskeletal Pain Outcomes Pre- and Post Intrathecal Baclofen Pump Implant in Children With Cerebral Palsy: A Prospective Cohort Study\u003c/strong\u003e. \u003cem\u003eArch Rehabil Res Clin Transl \u003c/em\u003e2020, 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dysregulation in children with cerebral palsy\u003c/strong\u003e. \u003cem\u003eDev Med Child Neurol \u003c/em\u003e2021, \u003cstrong\u003e63\u003c/strong\u003e(4):407-412.\u003c/li\u003e\n\u003cli\u003eSchleiss MR: \u003cstrong\u003eAltered cytokine responses in children with cerebral palsy: pathogenesis and novel therapies\u003c/strong\u003e. \u003cem\u003eDev Med Child Neurol \u003c/em\u003e2021, \u003cstrong\u003e63\u003c/strong\u003e(4):365-366.\u003c/li\u003e\n\u003cli\u003eHvingelby VS, Bjarkam CR, Mathiesen TI, Poulsen FR, Botker MT, Husted A, Korshoej AR: \u003cstrong\u003eThe prognostic significance of biomarkers in cerebrospinal fluid following severe traumatic brain injury: a systematic review and meta-analysis\u003c/strong\u003e. \u003cem\u003eNeurosurg Rev \u003c/em\u003e2022, \u003cstrong\u003e45\u003c/strong\u003e(4):2547-2564.\u003c/li\u003e\n\u003cli\u003eDietrick B, Molloy E, Massaro AN, Strickland T, Zhu J, Slevin M, Donoghue V, Sweetman D, Kelly L, O\u0026apos;Dea M\u003cem\u003e et al\u003c/em\u003e: \u003cstrong\u003ePlasma and Cerebrospinal Fluid Candidate Biomarkers of Neonatal Encephalopathy Severity and Neurodevelopmental Outcomes\u003c/strong\u003e. \u003cem\u003eJ Pediatr \u003c/em\u003e2020, \u003cstrong\u003e226\u003c/strong\u003e:71-79 e75.\u003c/li\u003e\n\u003cli\u003eBjurstrom MF, Bodelsson M, Irwin MR, Orbjorn C, Hansson O, Mattsson-Carlgren N: \u003cstrong\u003eDecreased pain sensitivity and alterations of cerebrospinal fluid and plasma inflammatory mediators after total hip arthroplasty in patients with disabling osteoarthritis\u003c/strong\u003e. \u003cem\u003ePain Pract \u003c/em\u003e2022, \u003cstrong\u003e22\u003c/strong\u003e(1):66-82.\u003c/li\u003e\n\u003cli\u003eHarris CA, Morales DM, Arshad R, McAllister JP, 2nd, Limbrick DD, Jr.: \u003cstrong\u003eCerebrospinal fluid biomarkers of neuroinflammation in children with hydrocephalus and shunt malfunction\u003c/strong\u003e. \u003cem\u003eFluids Barriers CNS \u003c/em\u003e2021, \u003cstrong\u003e18\u003c/strong\u003e(1):4.\u003c/li\u003e\n\u003cli\u003eGiron SE, Bjurstrom MF, Griffis CA, Ferrante FM, Wu, II, Nicol AL, Grogan TR, Burkard JF, Irwin MR, Breen EC: \u003cstrong\u003eIncreased Central Nervous System Interleukin-8 in a Majority Postlaminectomy Syndrome Chronic Pain Population\u003c/strong\u003e. \u003cem\u003ePain Med \u003c/em\u003e2018, \u003cstrong\u003e19\u003c/strong\u003e(5):1033-1043.\u003c/li\u003e\n\u003cli\u003eBo SH, Davidsen EM, Gulbrandsen P, Dietrichs E, Bovim G, Stovner LJ, White LR: \u003cstrong\u003eCerebrospinal fluid cytokine levels in migraine, tension-type headache and cervicogenic headache\u003c/strong\u003e. \u003cem\u003eCephalalgia \u003c/em\u003e2009, \u003cstrong\u003e29\u003c/strong\u003e(3):365-372.\u003c/li\u003e\n\u003cli\u003eSchiff MH: \u003cstrong\u003eRole of interleukin 1 and interleukin 1 receptor antagonist in the mediation of rheumatoid arthritis\u003c/strong\u003e. \u003cem\u003eAnn Rheum Dis \u003c/em\u003e2000, \u003cstrong\u003e59 Suppl 1\u003c/strong\u003e(Suppl 1):i103-108.\u003c/li\u003e\n\u003cli\u003eBessler H, Osovsky M, Beilin B, Alcalay Y, Sirota L: \u003cstrong\u003eThe existence of gender difference in IL-1Ra gene polymorphism\u003c/strong\u003e. \u003cem\u003eJ Interferon Cytokine Res \u003c/em\u003e2007, \u003cstrong\u003e27\u003c/strong\u003e(11):931-935.\u003c/li\u003e\n\u003cli\u003eKosek E, Finn A, Ultenius C, Hugo A, Svensson C, Ahmed AS: \u003cstrong\u003eDifferences in neuroimmune signalling between male and female patients suffering from knee osteoarthritis\u003c/strong\u003e. \u003cem\u003eJ Neuroimmunol \u003c/em\u003e2018, \u003cstrong\u003e321\u003c/strong\u003e:49-60.\u003c/li\u003e\n\u003cli\u003eZhao P, Zhu P, Zhang D, Yin B, Wang Y, Hussein NM, Yan Z, Liu X, Bai G: \u003cstrong\u003eSex Differences in Cerebral Blood Flow and Serum Inflammatory Cytokines and Their Relationships in Mild Traumatic Brain Injury\u003c/strong\u003e. \u003cem\u003eFront Neurol \u003c/em\u003e2021, \u003cstrong\u003e12\u003c/strong\u003e:755152.\u003c/li\u003e\n\u003cli\u003eHussein MH, Daoud GA, Kakita H, Hattori A, Murai H, Yasuda M, Mizuno K, Goto K, Ozaki Y, Ito T\u003cem\u003e et al\u003c/em\u003e: \u003cstrong\u003eThe sex differences of cerebrospinal fluid levels of interleukin 8 and antioxidants in asphyxiated newborns\u003c/strong\u003e. \u003cem\u003eShock \u003c/em\u003e2007, \u003cstrong\u003e28\u003c/strong\u003e(2):154-159.\u003c/li\u003e\n\u003cli\u003eSimonet WS, Hughes TM, Nguyen HQ, Trebasky LD, Danilenko DM, Medlock ES: \u003cstrong\u003eLong-term impaired neutrophil migration in mice overexpressing human interleukin-8\u003c/strong\u003e. \u003cem\u003eJ Clin Invest \u003c/em\u003e1994, \u003cstrong\u003e94\u003c/strong\u003e(3):1310-1319.\u003c/li\u003e\n\u003cli\u003eLi A, Dubey S, Varney ML, Dave BJ, Singh RK: \u003cstrong\u003eIL-8 directly enhanced endothelial cell survival, proliferation, and matrix metalloproteinases production and regulated angiogenesis\u003c/strong\u003e. \u003cem\u003eJ Immunol \u003c/em\u003e2003, \u003cstrong\u003e170\u003c/strong\u003e(6):3369-3376.\u003c/li\u003e\n\u003cli\u003eLauterbach MD, Raz S, Sander CJ: \u003cstrong\u003eNeonatal hypoxic risk in preterm birth infants: the influence of sex and severity of respiratory distress on cognitive recovery\u003c/strong\u003e. \u003cem\u003eNeuropsychology \u003c/em\u003e2001, \u003cstrong\u003e15\u003c/strong\u003e(3):411-420.\u003c/li\u003e\n\u003cli\u003eLin CY, Chang YC, Wang ST, Lee TY, Lin CF, Huang CC: \u003cstrong\u003eAltered inflammatory responses in preterm children with cerebral palsy\u003c/strong\u003e. \u003cem\u003eAnn Neurol \u003c/em\u003e2010, \u003cstrong\u003e68\u003c/strong\u003e(2):204-212.\u003c/li\u003e\n\u003cli\u003eGoracke-Postle CJ, Burkitt CC, Panoskaltsis-Mortari A, Ehrhardt M, Wilcox GL, Graupman P, Partington M, Symons FJ: \u003cstrong\u003eExpression of and correlational patterns among neuroinflammatory, neuropeptide, and neuroendocrine molecules from cerebrospinal fluid in cerebral palsy\u003c/strong\u003e. \u003cem\u003eBMC Neurol \u003c/em\u003e2021, \u003cstrong\u003e21\u003c/strong\u003e(1):384.\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003eTable 1. Means, medians, and one-sided non-parametric comparisons of analyte levels in cerebral spinal fluid for children with cerebral palsy collected during intrathecal baclofen pump implant surgery (T1) and at ITB pump refill visits (T2).\u0026nbsp;\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"946\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 10.4651%;\"\u003e\n \u003cp\u003eAnalyte\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8.45666%;\"\u003e\n \u003cp\u003e% values available for analyses (n=)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 12.0507%;\"\u003e\n \u003cp\u003eT1\u003c/p\u003e\n \u003cp\u003eMean (SD)\u003c/p\u003e\n \u003cp\u003epg/mL\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 13.7421%;\"\u003e\n \u003cp\u003eT2\u003c/p\u003e\n \u003cp\u003eMean (SD)\u003c/p\u003e\n \u003cp\u003epg/mL\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10.3594%;\"\u003e\n \u003cp\u003eT1\u003c/p\u003e\n \u003cp\u003eMedian (IQR)\u003c/p\u003e\n \u003cp\u003epg/mL\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10.3594%;\"\u003e\n \u003cp\u003eT2\u003c/p\u003e\n \u003cp\u003eMedian (IQR)\u003c/p\u003e\n \u003cp\u003epg/mL\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10.0423%;\"\u003e\n \u003cp\u003eMedian Difference\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6.65962%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e\u003cem\u003eV\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8.77378%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e\u003cem\u003ep\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 9.09091%;\"\u003e\n \u003cp\u003eEffect size,\u003cem\u003e\u0026nbsp;r\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 10.4651%;\"\u003e\n \u003cp\u003eNoradrenaline\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8.45666%;\"\u003e\n \u003cp\u003e100%\u003c/p\u003e\n \u003cp\u003e(n=14)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 12.0507%;\"\u003e\n \u003cp\u003e2.01 (1.42)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 13.7421%;\"\u003e\n \u003cp\u003e2.24 (1.26)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10.3594%;\"\u003e\n \u003cp\u003e1.58 (1.47)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10.3594%;\"\u003e\n \u003cp\u003e2 (1.64)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10.0423%;\"\u003e\n \u003cp\u003e0.42\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6.65962%;\"\u003e\n \u003cp\u003e58\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8.77378%;\"\u003e\n \u003cp\u003e0.377\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 9.09091%;\"\u003e\n \u003cp\u003e0.092\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 10.4651%;\"\u003e\n \u003cp\u003eIL-1RA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8.45666%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e92.9%\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e(n=13)*\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 12.0507%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e56.19 (47.98)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 13.7421%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e343.16 (323.88)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10.3594%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e38.4 (16.2)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10.3594%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e213.6 (493.6)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10.0423%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e175.2\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6.65962%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e89\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8.77378%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026lt;.001\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 9.09091%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e0.843\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 10.4651%;\"\u003e\n \u003cp\u003eIL-8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8.45666%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e92.9%\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e(n=13)*\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 12.0507%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e27.89 (12.34)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 13.7421%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e49.69 (29.75)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10.3594%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e23.5 (16.2)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10.3594%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e39.7 (49.5)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10.0423%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e16.2\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 6.65962%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e76\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8.77378%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.016\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 9.09091%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.591\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 10.4651%;\"\u003e\n \u003cp\u003eIL-10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 8.45666%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e92.9%\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e(n=13)*\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 12.0507%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.68 (0.09)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 13.7421%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.92 (0.53)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10.3594%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.7 (0.1)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10.3594%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.7 (0.3)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 10.0423%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e0\u003c/strong\u003e\u003c/p\u003e\n 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\u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e*IL-1RA: Post outlier value of \u0026gt;5050 removed; *IL-8: Post outlier value of 497.4 removed; *IL-10: Post outlier value of 5.5 removed; *MCP-1: Post outlier value of 1435.4 removed.\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-neurology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"nurl","sideBox":"Learn more about [BMC Neurology](http://bmcneurol.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/nurl","title":"BMC Neurology","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Intrathecal baclofen, pain, biomarkers, interleukin, cerebral spinal fluid, cerebral palsy, developmental disability","lastPublishedDoi":"10.21203/rs.3.rs-7277982/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7277982/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e\u003cp\u003eCerebral palsy (CP) is the most common cause of disability in children. Cerebral palsy (CP) is the most common cause of disability in children. For children with CP, muscle spasticity is often a cause of chronic pain. Surgical implant of an intrathecal baclofen (ITB) pump is a typical method to treat spasticity. Most studies have documented a reduction in spasticity upon ITB implant; however, less is known about other outcomes, including pain reduction. Little is known about spasticity-related muscle pain in general. Sustained muscle fiber contraction over time, resulting in local ischemia, may result in pathological inflammatory and nociceptive consequences affecting excitatory or inhibitory circuits peripherally but also centrally. Examining inflammatory and nociceptive biomarkers could be especially important in children with CP, who have high rates of chronic pain and typically undergo multiple surgeries in their lifetime. Surgery has been associated with increases in inflammatory biomarker levels which predict important outcomes such as time to healing. This study investigated changes in levels of nociceptive and inflammatory-relevant molecules in cerebral spinal fluid (CSF) from a clinical-convenience sample of children with CP being treated for spasticity through standard-of-care ITB pump implant surgery for hypothesis-generating research purposes.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e\u003cp\u003eFourteen children with CP participated (7 male, mean age at surgery\u0026thinsp;=\u0026thinsp;9 years, 8 months [SD\u0026thinsp;=\u0026thinsp;2.25]). CSF was collected during surgery and again, on average, 8.5 months (SD\u0026thinsp;=\u0026thinsp;4.4) after surgery during baclofen pump refill. Wilcoxon signed rank tests were used to compare analyte levels.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e\u003cp\u003eSignificant differences were observed for the rank ordered values (pg/ml) for the three interleukins (IL-1RA: Median pre\u0026thinsp;=\u0026thinsp;38.4/post\u0026thinsp;=\u0026thinsp;213.6; IL-8: Median pre\u0026thinsp;=\u0026thinsp;23.5/post\u0026thinsp;=\u0026thinsp;39.7; IL-10: Median pre\u0026thinsp;=\u0026thinsp;0.7/post\u0026thinsp;=\u0026thinsp;0.7 [Mean values for IL-10 were pre\u0026thinsp;=\u0026thinsp;0.68/post\u0026thinsp;=\u0026thinsp;0.92], p\u0026thinsp;\u0026lt;\u0026thinsp;.05).\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e\u003cp\u003eThe main but tentative preliminary finding points to increased analyte levels from the interleukin family. Interleukins regulate immune responses often with pro- and anti-inflammatory properties. Our observations of increased CSF IL-10 and IL-8 are consistent with similar observations of increases post-procedure and some limited observations of IL-1RA elevations in chronic pain. Understanding inflammatory response profiles in CP could lead to important treatment and pain outcome implications.\u003c/p\u003e","manuscriptTitle":"An exploratory investigation of neuroinflammatory and nociceptive biomarkers from cerebrospinal fluid in children with cerebral palsy following intrathecal baclofen pump implant surgery","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-11-13 07:51:48","doi":"10.21203/rs.3.rs-7277982/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"editorInvitedReview","content":"","date":"2025-11-25T06:16:49+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-11-19T06:16:07+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-11-17T06:07:59+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-11-17T05:24:43+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"328195081760413730596948370346135109471","date":"2025-11-14T11:04:21+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-11-13T09:32:37+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"240850967178026767278265369538241085815","date":"2025-11-13T06:26:41+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-11-13T03:05:40+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"162365357086280532065185809269946885873","date":"2025-11-13T02:23:21+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-11-12T03:33:37+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"12207316738914812819211723567829440638","date":"2025-11-10T09:04:54+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"92626872070296735232191283345962837394","date":"2025-11-10T07:06:14+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"28145869965223773702735187027240986667","date":"2025-11-10T06:31:49+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"336335841141627387575475857334848917724","date":"2025-11-10T03:03:15+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"15535235164525548486769900864573185992","date":"2025-11-10T01:37:20+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"32370899006066282312069725490372436645","date":"2025-11-09T16:59:58+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-10-31T13:36:05+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-08-24T07:04:44+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2025-08-22T12:02:58+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-08-20T19:12:48+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Neurology","date":"2025-08-20T19:09:50+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-neurology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"nurl","sideBox":"Learn more about [BMC Neurology](http://bmcneurol.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/nurl","title":"BMC Neurology","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"f8fcc89a-3cad-437d-ac3f-58e9eac09a28","owner":[],"postedDate":"November 13th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2025-11-13T07:51:49+00:00","versionOfRecord":[],"versionCreatedAt":"2025-11-13 07:51:48","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7277982","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7277982","identity":"rs-7277982","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}